---
name: "rapiddisk"
section: "1"
platform: "linux"
package: "rapiddisk"
version: "9.2.0-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/rapiddisk"
---

# rapiddisk(1)

An administration tool to manage the RapidDisk RAM disk devices and RapidDisk-Cache mappings.

## NAME

rapiddisk - An administration tool to manage the RapidDisk RAM disk devices and RapidDisk-Cache mappings.

## SYNOPSIS

rapiddisk \[ -h \| -v \] function \[ parameters \]

## DESCRIPTION

rapiddisk is a RapidDisk module management tool to manage RapidDisk RAM disk devices. Dynamically create, remove, resize RAM volumes and if desired, map or unmap them as a cache volume to any block device. Access those drives locally or export those volumes across an NVMe Target network.

### Options

- \-h

  Invoke the help menu.

- \-v

  Display the version number.

### Functions

- \-a

  Attach RAM disk device (size in MBytes).

- \-b

  Backend block device absolute path (for cache mapping).

- \-c

  Input capacity for size or resize of RAM disk device (in MBytes).

- \-d

  Detach RAM disk device.

- \-e

  Export a RapidDisk block device as an NVMe Target.

- \-f

  Erase all data to a specified RapidDisk device (dangerous).

- \-g

  Do not print header.

- \-H

  The host to export / unexport the NVMe Target to / from.

- \-i

  Define the network interface to enable for NVMe Target exporting. Port must not already exist and interface must not be already enabled.

- \-j

  Enable JSON formatted output.

- \-L

  Lock a RapidDisk block device (set to read-only).

- \-l

  List all attached RAM disk devices.

- \-m

  Map an RapidDisk device as a caching node to another block device.

- \-N

  List only enabled NVMe Target ports.

- \-n

  List RapidDisk enabled NVMe Target exports.

- \-P

  The port to export / unexport the NVMe Target to / from.

- \-p

  Define cache policy: write-through (wt), write-around (wa) or writeback (wb) (dangerous) (default: write-through). Writeback caching is supplied by the dm-writecache kernel module and is not intended for production use as it may result in data loss on hardware/power failure.

- \-q

  List all system memory and block device resources.

- \-R

  Revalidate size of NVMe export using existing RapidDisk device.

- \-r

  Dynamically grow the size of an existing RapidDisk device.

- \-s

  Obtain RapidDisk-Cache Mappings statistics.

- \-t

  Define the NVMe Target port's transfer protocol (i.e. tcp, rdma or loop).

- \-U

  Unlock a RapidDisk block device (set to read-write).

- \-u

  Unmap a RapidDisk device from another block device.

- \-X

  Remove the NVMe Target port (must be unused).

- \-x

  Unexport a RapidDisk block device from an NVMe Target. To remove export to host or port, only define the host and / or port. Not defining a host or port will result in the block device being removed from the NVMe Target subsystem.

### Parameters (if applicable)

- \[size\]

  Specify desired size of attaching RAM disk device in MBytes.

- \[mode\]

  Write Through (wt) or Write Around (wa) for cache.

## EXAMPLE USAGE

- rapiddisk -l

  - rapiddisk -l -j

  - rapiddisk -a 64

  - rapiddisk -d rd2

  - rapiddisk -r rd2 -c 128

  - rapiddisk -m rd1 -b /dev/sdb

  - rapiddisk -m rd1 -b /dev/sdb -p wt

  - rapiddisk -m rd3 -b /dev/mapper/rc-wa\_sdb -p wb

  - rapiddisk -u rc-wt\_sdb

  - rapiddisk -s rc-wt\_sdb

  - rapiddisk -f rd2

  - rapiddisk -L rd2

  - rapiddisk -U rd3

  - rapiddisk -i eth0 -P 1 -t tcp

  - rapiddisk -i NULL -P 1 -t loop

  - rapiddisk -X -P 1

  - rapiddisk -e -b rd3 -P 1 -H nqn.host1

  - rapiddisk -R -b rd0

  - rapiddisk -x -b rd3 -P 1 -H nqn.host1

  ## MANAGING RAPIDDISK AS AN NVME TARGET

There are a few things that need to be known when using the NVMe Target features of the RapidDisk suite.

- 1\.

  In order to map any RapidDisk device and export it in the NVMe Target framework, the nvmet and the nvmet-tcp or nvmet-rdma kernel modules must be inserted.

- 2\.

  At least one Ethernet interface will need to be configured as a target port to export the RapidDisk volume from.

  ex) rapiddisk -i eth -P 1 -t tcp

- 3\.

  When exporting a volume, a RapidDisk volume and a target port must be defined. If a host NQN is not defined, the administration utility will provide access to any host NQN. Note - a target can be exported across more than one target port.

  ex) rapiddisk -e -b rd3 -P 1

  If a host NQN is defined, access is restricted to only those host NQNs. Note - the following command example can be repeated multiple times to add additional host NQNs for the specified target export.

  ex) rapiddisk -e -b rd3 -P 1 -H nqn.host1

- 4\.

  Unexporting RapidDisk volumes looks a bit different than exporting. If a host NQN is defined for a specified target, only that NQN will be removed from accessing the exported target.

  ex) rapiddisk -x -b rd3 -H nqn.host1

  Removing all allowed host NQNs will revert access to any and all host NQNs requesting access to the target.

  If a target port is defined, the exported target will not be exported from the interface if one condition is met: the target has no defined allowed host NQNs.

  ex) rapiddisk -x -b rd3 -P 1 -H nqn.host1

  ex) rapiddisk -x -b rd3 -P 1

  And if there are no defined allowed host NQNs and the target is not being exported across any target ports, the entire target is removed from the subsystem.

## EXIT STATUS

rapiddisk returns a zero exit status if no error occurs during operation. A non-zero value is returned on error.

## AUTHORS

Original version: Petros Koutoupis (petros@petroskoutoupis.com)

## SEE ALSO

View the RapidDisk project page: http://www.rapiddisk.org